Efficacy of inactivated whole HIV-2 vaccines with various adjuvants in cynomolgus monkeys.

Twenty-one cynomolgus monkeys were immunized with whole inactivated HIV-2 preparations administered with various adjuvants (incomplete Freund's adjuvant, Alum, Ribi, MDP, or Iscoms) and challenged with 10 or 100 MID50 of a homologous monkey-cell grown, cell-free HIV-2. Seven animals were completely protected against infection, three showed reduced virus replication. The vaccines elicited neutralizing and ADCC antibodies; the titers did not correlate with protection. Immunization with a whole inactivated vaccine can protect primates from intravenous challenge with a monkey-cell grown cell-free human immunodeficiency virus type 2.